Here is some more advice. A snippet from Wolfram....
For example, in the TMJ stylesheet, you can edit the Working style to
understand printing margins by adding the following options to the section
Style Environment Names -> Working: (use Ctrl-Shift-e to open the
section)
PageWidth->PaperWidth,
PrintingOptions->{"PageSize"->{490, 720},
"PrintingMargins"->{{0, 0}, {82, 56}}},
If you are working on a custom stylesheet, you can copy the Style
Enviornment Names section out of Core.nb, paste it into your stylesheet,
and make the changes there.
Adding these options and setting the Printing Environment to Working will
allow you to make PDFs that more closely match what you see on the screen.
Cheers,
t.